The continuing development of mine safety regulations has contributed greatly to the reduction of accidental injuries in mining operations. The increased use of automated machinery is a result of industry efforts to provide personnel safety and maintain or increase production. The use of automated machinery removes personnel from the most dangerous areas of the mine; the working face and the unsupported roof of the mine shaft. Introducing machines into the mine near the working face results, in effect, in the addition of another hazard to the personnel.
In the forward portion of the working face there are conditions of very confined spaces, loud noise, and restricted visibility. When miners are working on opposite sides of a machine each is frequently out of sight of the other. The machines are usually electrically powered and hydraulically controlled and move with such force that they can easily injure, maim or kill.
Specifically, the dual boom roof bolting operation which this invention is concerned with requires two miners whose work stations, while in the bolting operation, are on opposite sides of the roof bolting machine. Each miner operates a hydraulically powered roof bolting boom to drill holes in the unsupported roof and place reinforcing roof bolts therein. The booms have controls to operate independently of each other and are capable of moving horizontally and vertically in the mine shaft. With current machinery, it is possible for one of the miners to leave his position and move about the front area of the machine while the other miner is operating the apparatus. Such conditions invite an accident.
The dual boom roof bolting machine of this invention is a mobile apparatus which can be attached to the front end of a conventional tramming vehicle. Tramming vehicles have powered wheels and usually carry the hydraulic pumps, reservoirs, with associated valving, and other required accessories, such as electrical connections, with them to the working face of the mine. The tramming vehicle has controls for forward and reverse movement conventionally placed at or near the rear of the vehicle and are used primarily for moving the machine to and from the working face. At this position, the operator cannot see the periphery of the vehicle or the attached roof bolting machine. The other operator may not be visible when the vehicle is moved, again inviting an accident.